The present invention relates to a method for recycling a waste material of a thermoplastic resin molded article as resources.
Conventionally, some bumpers for an automotive vehicle as a waste material have been collected and pulverized, and resin materials for recycling have been obtained from the pulverized bumpers.
Herein, it is generally necessary that metal materials are removed from the pulverized bumper pieces obtained, then target resin materials for recycling are selected from the bumper pieces without the metal materials, and coating films coated on the selected resin materials are peeled from their resin substrates.
Japanese Patent Laid-Open Publication No. 2002-254430 discloses a crasher operative to crash (pulverize) resin molded articles, such as PET bottles, and a centrifugal separator operative to separate specified resin-material pieces from the crashed (pulverized) pieces according to difference in specific gravity thereof.
Japanese Patent Laid-Open Publication No. 2006-15721 discloses a metal selection device operative to select metal-based pieces from crashed pieces of thermoplastic resin molded articles by using magnets, and a mixing tank operative to select target resin-material pieces from the crashed pieces without metal-based pieces according to the specific gravity difference.
Herein, in a case where resin-material pieces still having coating films coated thereon are used as recycling materials, there is a concern that recycled products obtained may provide poor physical properties or poor appearances. The above-described publications disclose no specific treatments of peeling the coating films from substrates of the crashed resin-material pieces.